As a substance for preventing fungal outbreak or bacterial growth in food, a volatile oily antibacterial substance such as an isothiocyanate ester represented by allyl isothiocyanate is known. However, since the volatility of the substance is high, it has a characteristic that its effect is decreased in an extremely short time. Therefore, it has a problem in the duration of the effect itself. Accordingly, as one of the means of solving such a problem, a method of forming a humidity-dependent antibacterial powdery composition by enclosing a volatile oily antibacterial substance in a cyclodextrin so as to release the substance only in a high humid atmosphere and employing the composition has been proposed (see, for example, Japanese Patent No. 2,790,772). If a volatile oily antibacterial substance is enclosed in a cyclodextrin, chemical stability, deodorization, antioxidation, photodegradation inhibition, etc. of the substance can be attained, therefore, this method is an excellent method. However, since at most only an equivalent molar amount of volatile oily antibacterial substance is enclosed in the cyclodextrin, the ratio of the substance contained in the antibacterial powdery composition is at most only about 10% by weight. In addition, this antibacterial powdery composition is difficult to release the volatile oily antibacterial substance unless it is in an atmosphere of 90% or higher humidity, therefore, there remains room for improvement in the applicability.
It is therefore an object of the present invention to provide a humidity-dependent antibacterial powdery composition of excellent applicability wherein a volatile oily antibacterial substance can be contained in high ratio; a process for producing the same; a humidity-dependent antibacterial food storing article; and a method of storing food.